Update the code to use the term "rail" when dealing with a motor
controlled "axis". A rail has a series of steppers and endstops that
control that motor controlled "axis".
Signed-off-by: Kevin O'Connor <kevin@koconnor.net>
Add additional wrapper functions so that no outside callers need to
peak into the member variables of PrinterStepper.
Signed-off-by: Kevin O'Connor <kevin@koconnor.net>